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EC number: 405-800-7 | CAS number: 27955-94-8 THPE; TRIS(P-HYDROXYPHENYL)ETHANE; TRIS(PARA-HYDROXYPHENYL)ETHANE
- Life Cycle description
- Uses advised against
- Endpoint summary
- Appearance / physical state / colour
- Melting point / freezing point
- Boiling point
- Density
- Particle size distribution (Granulometry)
- Vapour pressure
- Partition coefficient
- Water solubility
- Solubility in organic solvents / fat solubility
- Surface tension
- Flash point
- Auto flammability
- Flammability
- Explosiveness
- Oxidising properties
- Oxidation reduction potential
- Stability in organic solvents and identity of relevant degradation products
- Storage stability and reactivity towards container material
- Stability: thermal, sunlight, metals
- pH
- Dissociation constant
- Viscosity
- Additional physico-chemical information
- Additional physico-chemical properties of nanomaterials
- Nanomaterial agglomeration / aggregation
- Nanomaterial crystalline phase
- Nanomaterial crystallite and grain size
- Nanomaterial aspect ratio / shape
- Nanomaterial specific surface area
- Nanomaterial Zeta potential
- Nanomaterial surface chemistry
- Nanomaterial dustiness
- Nanomaterial porosity
- Nanomaterial pour density
- Nanomaterial photocatalytic activity
- Nanomaterial radical formation potential
- Nanomaterial catalytic activity
- Endpoint summary
- Stability
- Biodegradation
- Bioaccumulation
- Transport and distribution
- Environmental data
- Additional information on environmental fate and behaviour
- Ecotoxicological Summary
- Aquatic toxicity
- Endpoint summary
- Short-term toxicity to fish
- Long-term toxicity to fish
- Short-term toxicity to aquatic invertebrates
- Long-term toxicity to aquatic invertebrates
- Toxicity to aquatic algae and cyanobacteria
- Toxicity to aquatic plants other than algae
- Toxicity to microorganisms
- Endocrine disrupter testing in aquatic vertebrates – in vivo
- Toxicity to other aquatic organisms
- Sediment toxicity
- Terrestrial toxicity
- Biological effects monitoring
- Biotransformation and kinetics
- Additional ecotoxological information
- Toxicological Summary
- Toxicokinetics, metabolism and distribution
- Acute Toxicity
- Irritation / corrosion
- Sensitisation
- Repeated dose toxicity
- Genetic toxicity
- Carcinogenicity
- Toxicity to reproduction
- Specific investigations
- Exposure related observations in humans
- Toxic effects on livestock and pets
- Additional toxicological data
![](https://echa.europa.eu./o/diss-blank-theme/images/factsheets/A-REACH/factsheet/print_physical-and-chemical-properties.png)
Dissociation constant
Administrative data
Link to relevant study record(s)
- Endpoint:
- dissociation constant
- Type of information:
- experimental study
- Adequacy of study:
- weight of evidence
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- guideline study
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 112 (Dissociation Constants in Water)
- Deviations:
- no
- Remarks:
- The study was conducted according to the test guidelines in effect at the time of study conduct.
- GLP compliance:
- yes
- Dissociating properties:
- no
- Conclusions:
- Employing methods described in this report, it was not possible to determine the pKa values for the test substance.
- Executive summary:
Potentiometric titration with a glass, hydrogen selective electrode was used for the determination of the acid dissociation constant (pKa) of the test substance at 24 ± 1°C. Test solutions of approximately 125 mg a.i./L were prepared in purified reagent water employing acetone at approximately 1% as a co-solvent to enhance test substance solubility. The solutions were titrated with 0.1 N sodium hydroxide over a pH range of approximately 8 to 11.
Phenols typically have a pKa in the range of 10 to 11 depending on the ring substituents. Testing was conducted at 24 ±°C with the test substance at a concentration of 125 mg a.i./L. Samples were titrated with 0.1 N sodium hydroxide and did not result in a definable endpoint typical for a phenol. This is due, in part, to the low water solubility (25.1 mg/L) of the test material and the inherent difficulties of determining pKa values in the pKa 10 range using potentiometric methodologies. Triplicate titrations showed no definable endpoint.
- Endpoint:
- dissociation constant
- Type of information:
- (Q)SAR
- Adequacy of study:
- weight of evidence
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- results derived from a (Q)SAR model, with limited documentation / justification, but validity of model and reliability of prediction considered adequate based on a generally acknowledged source
- Justification for type of information:
- QSAR prediction
- Principles of method if other than guideline:
- Four different approaches to generate a pKa for the test substance were used. These were ACD Labs v12.0, SPARC v4.5, Pipeline Pilot v12.0, and a substituent fragment method.
- GLP compliance:
- no
- Dissociating properties:
- no
- pKa:
- 10
- Temp.:
- 25 °C
- Remarks on result:
- other: Four approaches give comparable pKa values, and are in agreement with what a pKa would be expected for a phenol (phenol pKa measured value of 9.99). Accordingly, a pKa for the test substance would be expected to be on the order of 10.
- pKa:
- 10.02 - 11.3
- Temp.:
- 25 °C
- Remarks on result:
- other: ACD Labs v12.0; temperature not reported in models, so standard temperature of 25°C is assumed.
- pKa:
- 9.99 - 10.29
- Temp.:
- 25 °C
- Remarks on result:
- other: SPARC v4.5; temperature not reported in models, so standard temperature of 25°C is assumed.
- pKa:
- 9 - 11.16
- Temp.:
- 25 °C
- Remarks on result:
- other: Pipeline Pilot v12.0; temperature not reported in models, so standard temperature of 25°C is assumed.
- pKa:
- 10.21
- Temp.:
- 25 °C
- Remarks on result:
- other: Substituent fragment method; temperature not reported in models, so standard temperature of 25°C is assumed.
- Conclusions:
- The pKa of the test substance would be expected to be of the order of 10.
- Executive summary:
Four different approaches to generate a pKa for the test substance were used. These were ACD Labs v12.0, SPARC v4.5, Pipeline Pilot v12.0, and a substituent fragment method as reported in Perrin DD, Dempsey B, and Serjeant EP (1981). pKa prediction for organic acids and bases. Chapman and Hall, London and New York. The four approaches give comparable results for the pKa for the test substance, which are all in good agreement with what a pKa would be expected for a phenol. As part of a weight of evidence approach, the estimated pKa values derived are in good agreement with that for phenol itself, which has a measured value of 9.99. Accordingly, a pKa of the test substance would be expected to be of the order of 10.
Referenceopen allclose all
The temperature of all the test solutions remained within the acceptable range of 24 ± 1°C during all titrations. The pH of the test substance solutions was approximately 10 to 11 at the end of the titration with 0.1N sodium hydroxide.
The authors acknowledge that phenols typically have pKa values of approximately 10 to 11. In an attempt to measure pKa values in this range, a test was performed using a 0.1 N sodium hydroxide titrant since titration with 0.01 N sodium hydroxide did not yield solutions with pH values in that range. While the maximum pH of these solutions was >12, these titrations using 0.1 N sodium hydroxide did not yield any additional pKa values. This is likely due to the limited water solubility of the material (25.1 mg/L) and the relatively high titrant concentration required to achieve solutions with pH >10. Employing methods described in this report, it was not possible to determine the pKa values for the test substance.
Derived pKa estimates |
|||
ACD Labs v12.0 |
SPARC |
Pipeline Pilot |
Perrin |
10.02 |
9.99 |
9 |
10.21 |
10.79 |
10.14 |
10.08 |
|
11.30 |
10.29 |
11.16 |
|
The four approaches give comparable results for the pKa for the test substance, which are all in good agreement with what a pKa would be expected for a phenol. As part of a weight of evidence approach, the estimated pKa values derived are in good agreement with that for phenol itself, which has a measured value of 9.99. Accordingly, a pKa of the test substance would be expected to be of the order of 10.
Phenol:
pKa =9.99 at 25°C (Lide DR (ed.) (2002-2003). CRC Handbook of Chemistry and Physics, 83rded., p. 8-49, CRC Press, Inc., Boca Raton, FL.
Description of key information
Weight of evidence
Key value for chemical safety assessment
- pKa at 20°C:
- 10
Additional information
A pKa for the test substance would be expected to be on the order of 10.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
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